A recording made of transmissions from a personal implant that perceived everything that happened to that individual.

On this alternate Earth, everyone had a Companion implant that constantly transmitted the minutia of your life to an archive.

"Since the day you were born, you've had a personal recording cube in the alibi-archive pavilion adjacent to this very Council building. And it has recorded everything you've done, every moment of your life, as transmitted by your Companion.
"And ... every day of your life, you enjoy the peace and safety made possible by that very recording... You know that as you walk at night, the chances of you being the victim of robbery or murder ... are almost zero, because there's no way to get away with such a crime."